Rose, Rosa damascena, ext.

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 05 to 21 September 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP certificate (inspected on 13 and 14 October 2014 / signed on 8 April 2015)

Type of method:

method to determine freezing temperature

Key result

Melting / freezing pt.:

< 20 °C

Pre-test

The test item was filled into glass vessels and stored at a nominal temperature of - 80, – 20 and 5 °C.

Table 1.-Values Pre-Test

Room Temperature	3.5°C	-20.1°C	-80°C
slightly viscous liquid*	nearly to solid*	paste-like solid*	paste-like solid*

*visual control

The pre-test did not allow to determine a clear phase transition of the substance and a visual control of the appearance of the substance appeared not sufficient to determine clearly the physical state of the substance at the tested temperatures.To better understand the behavior of the substance with a decreasing of temperature, another pre-test was performed in cooling bath of a mixture of acetone and dry ice.

Pre-test Freezing point

A cooling bath with a mixture of acetone and dry ice was prepared. A thermometer (testo 720) for measuring the temperature of the cooling bath was set in. The test tube (30 * 300 mm) containing 20 mL test item and a thermometer (TTI 9) to measure the temperature of the test item were fixed on a stand above the test tube. The test tube was then moved into the cooling bath and the thermometer was introduced in the test substance. During the cooling down phase, the test item was stirred vigorously with a stainless steel wire sling.

At approx. -20 °C the test item was paste-like solid and the colour was separated to yellow-orange and brown. The physical state of the substance was evaluated first with a stirrer and later (because the stirrer got stuck) with another very long thin wire, wich was in the test vessel as well.

The test item was more and more harder but no constant temperature of the test item was observed down to – 74.7 °C (temperature of cooling bath – 79.5 °C) and no clear freezing point of the test item was determined down to -74.7 °C. The test was stopped.

After stopping the appearance of the test item returned to normal state at room temperature.

No observations were made which might cause doubts on the validity of the study outcome.Therefore, the result of the study is considered valid.

Conclusions:

The freezing point of test item was stated as < - 20 °C (< 253.15 K). No further testing is required.

Executive summary:

The freezing point of the test substance was determined under GLP according to OECD 102 / EU A1 guideline.

In a pre-test; the test item was filled into glass vessels and stored at – 80, – 20 and 5 °C for a period of 24 hours. This pre-test did not show a clear phase transition of the substance. Another pre-test was then performed in cooling bath of a mixture of acetone and dry ice. The substance was not really solid at down to -74.7°C and finally, no constant temperature, which would demonstrate a phase transition, was observed.

Therefore no clear phase transition and no freezing point was determined down to -74.7 °C.

 

According to Regulation (EC) No 1907/2006 (REACH) annex VII, column 2 of section 7.2, the determination of the melting- / freezing point does not need to be conducted below a lower limit of - 20 °C. Therefore no additional test was conducted considering that the test item was still liquid (not really solid) at -20°C.

Description of key information

The freezing point of the test item was determined as < - 20 °C (< 253.15 K). No further testing required.

Additional information

A reliable GLP experimental study, conducted according to a recognized OECD/EC guidelines is available.

It is considered as a key study.